From: Adam Sampson ats@offog.org
[ Upstream commit b3168c87c0492661badc3e908f977d79e7738a41 ]
Because the brightness and contrast controls share a register, usbtv_s_ctrl needs to read the existing values for both controls before inserting the new value. However, the code accidentally wrote to the registers (from an uninitialised stack array), rather than reading them.
The user-visible effect of this was that adjusting the brightness would also set the contrast to a random value, and vice versa -- so it wasn't possible to correctly adjust the brightness of usbtv's video output.
Tested with an "EasyDAY" UTV007 device.
Fixes: c53a846c48f2 ("usbtv: add video controls")
Signed-off-by: Adam Sampson ats@offog.org Reviewed-by: Lubomir Rintel lkundrak@v3.sk Signed-off-by: Hans Verkuil hans.verkuil@cisco.com Signed-off-by: Mauro Carvalho Chehab mchehab@s-opensource.com Signed-off-by: Sasha Levin alexander.levin@verizon.com --- drivers/media/usb/usbtv/usbtv-video.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c index 95b5f4319ec2..3668a04359e8 100644 --- a/drivers/media/usb/usbtv/usbtv-video.c +++ b/drivers/media/usb/usbtv/usbtv-video.c @@ -718,8 +718,8 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) */ if (ctrl->id == V4L2_CID_BRIGHTNESS || ctrl->id == V4L2_CID_CONTRAST) { ret = usb_control_msg(usbtv->udev, - usb_sndctrlpipe(usbtv->udev, 0), USBTV_CONTROL_REG, - USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, + usb_rcvctrlpipe(usbtv->udev, 0), USBTV_CONTROL_REG, + USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 0, USBTV_BASE + 0x0244, (void *)data, 3, 0); if (ret < 0) goto error;